The initial step in building a cabin is to prepare the site. Construction of the foundation, walls, and roof comes next. One of the final jobs is to install the windows and doors. Although windows and doors are among the last items completed, they must be planned from the first to ensure that the rules of sound building design are followed. One rule is that wall openings for doors and windows should be located away from corners. Another is that the openings must not penetrate either the sill log or the top plate. Normally at least two logs should span the space above a doorway or window, although in a small cabin with no upper loft the log below the plate can be partially cut away.
Cut out door and window openings after the walls are completed or prepare them for cutting during the building process. Kit homes save on lumber by using logs that have been precut to conform to the precise window and door openings specified in the plans. Once the wall is up and the openings are made, use rough-cut commercial lumber to build the frames. Since the bottom of a door frame serves as a threshold, it should be made of a hardwood, such as oak. Notch and flatten the top and bottom logs, and then fit in the frame by one of the methods shown below. Be sure to slope the flattened surface of the bottom logtoward the outside so that water can drain away. Allow several inches for settling between the frame and the top log, and chink the gap with fiberglass insulation protected by metal flashing as shown below. It is best to have the doors and windows on hand when the wall openings are cut.

Installing a splined frame

Flatten log that will be at bottom of window, and mark width of frame on it. As each log is laid in place, bore 1 1/2-in. holes through it (left). Bore outside of the mark on both sides of the opening. When top of frame is reached, attach 2 × 6 guides and saw down through each log (right), cutting through the edge of the holes nearest the opening to form vertical grooves.
Splined frame fits in grooved opening. Chisel groove square or trim with tip of chain saw. Assemble frames and nail 1 1/2-in.-sq. strips along outside edges. Work frame into place before attaching top log. Caulk gaps with sealer.
Log walls may settle up to 4 in., so provide an extra space allowance above openings. Fill the gap with fiberglass insulation that compresses as logs descend. install protective copper flashing on the top log above the insulation for weather seal.
Fitting a nailed frame
Nailed frame can be fitted after wall is completed. saw out opening to match frame dimensions. Allow extra room at top. Assemble frame and nail it onto log ends through slotted frame sides to allow settling. Caulk with sealer.Notch joists carefully into sill logs for a level floor. Use string and a line level to ensure that bearing surfaces of all sill notches are at the same height. When cutting the ends of joists, hew top surfaces flat, then measure down from the top and trim excess from beneath. Commercial 2 × 10’s can also be used as joists.

Putting a Floor in Your Cabin

Unless your cabin is set directly on the ground, the floor must be supported by joists. These are beams spanning the distance between sill logs or between sills and a center floor girder if the distance between sills is more than 10 feet. The girder, like the sills, must be supported by the foundation. Notch the sills (and girder) to take the joist ends after the second round of logs is in place. All notches must be carefully cut to the same depth.
Logs for joists should be 6 to 8 inches in diameter and be hewn flat on top. Joists of 2 × 10 commercial lumber can also be used. They generally produce a more level floor and are just as strong as logs. Space joists at even intervals, between 16 inches and 2 feet apart center to center. The flooring itself consists of two layers: a subfloor and a finish floor. The subfloor can be made of 1 × 8 tongue-and-groove lumber, 3/4-inch plywood, or particle board. Traditionally, the finish floor is made of wide pine planks; hardwood, such as oak or maple, will wear better, however. Fasten the finish floor with cut nails for an authentic appearance. Or simulate a pegged floor by countersinking screws and concealing them beneath dowel plugs. Tar paper is often placed on the subfloor to prevent dampness. Insulation beneath the subfloor will cut down on heat loss.

Raising the Roof Beams

Two traditional roof styles—rafter and purlin—are illustrated on following page. Rafter-style roofs require ceiling joists or tie beams to prevent the walls from spreading outward, since the vertical load of the roof exerts downward pressure at an angle on the cabin sides. Purlin roofs produce no spreading even under tremendous snow loads because vertical pressure is not transferred at an angle but instead is supported directly beneath by long horizontal logs resting on the end walls of the cabin. Although tie beams are not required for the walls when a purlin roof is used, they are generally installed anyway as parts of the trusses that support the purlins themselves. Without trusses the purlins of any but small cabins may sag under their own weight.
The first step in making either style of roof is to install plates—large logs similar to sills that are notched to take the ceiling joists, tie beams, or trusssupports. The plates should also be notched to take the rafter ends unless extra, courses of wall logs are to be added to form a second-story loft.
Gable ends rise to a peak at each end of the cabin. In a rafter-style roof they can be built after the rest of the roof is completed. One type of gable consists of horizontal or vertical log sections spiked together and trimmed to the angle of the roof pitch. Another kind, shown at right, is built like an ordinary exterior frame wall. Panel the exterior of the gables with lumber siding or log slabs. Gables for a purlin roof (also illustrated at right) are made of horizontal log sections spiked one on top of another and notched to take each purlin as it is set in place during the building sequence. Afterward, the angle of the roof pitch is marked and the log ends are trimmed off with a saw.

Details of rafter installation

Traditional angle of roof pitch is 45°, steep enough to shed snow from roofing. To determine rafter length (A), divide length of end wall (B) by 1.4, then add additional 18 in. for trimming (more if an eave overhang is desired).
Cut right-angle notch in each rafter where it attaches to the plate. Vary the depth of the notches to compensate for variations in rafter thicknesses. if the plate is uneven, notch it to equalize depths, using level line as guide.
To match rafter ends at peak when ridgepole is not used, overlap each pair and saw both at once. Before cutting, make sure plate-notched ends are set correct distance apart. Nail 1x 6 collar tie across joint for extra strength.Raise preassembled rafter pairs by resting ends on plate logs, then pushing peak upright with pole. spike rafters to plate at notches; brace until decking is installed. Permanent braces are required in windy or heavy snow areas.

Rafter-style roof with framed gable ends

In rafter-style roofs, plates are spiked or pegged in place (far left). install tie beams in plate notches cut on 2-ft. centers. For rafters use logs or 2 x 8 lumber spaced 2 ft. apart. Notch rafters and spike to plate. Nail tops to ridgepole, or assemble rafter pairs on ground and erect as units. Logs can be added above plates (near left) to increase attic space.

Purlin roof with log gable ends
ming final angle of gable ends. Allow for the fact that purlins will be set in notches that are half their diameters. support purlins with trusses every 12 ft. (far right).

Raising the Walls

After the foundation has been laid and the sill logs and end logs that form the base of the cabin have been set in place, the next step is to raise the walls. Decide before starting how the floor will be built (see p.26), whether or not to use the chinkless method of stacking the logs described on page 29, and also whether you will use short precut logs to frame the window and door openings as the walls go up, or saw out these openings later from the solid walls as builders of traditional cabins usually do.
The basic steps in constructing the walls are hoisting the logs into position, aligning them so that they are vertical and at right angles to each other at the corners, and notching them so that they lock permanently in place. Since logs weigh several hundred pounds each, lifting is best done with mechanical assistance. Two traditional methods are shown below. Plenty of manpower helps too—not just to make the job easier but to make it safer as well. Once a log is up it should be carefully positioned for notching with the help of carefully aligned sighting poles driven into the ground a short distance from each corner. Sight along the log’s length to make sure its center is lined up with the poles.
After a log is in place for notching, scribe it at both ends, roll it over, and use log dogs to fasten it to neighboring logs while you cut the notch. For safety, always roll logs toward the center of the wall. Most logs have a crown, or slight bow along their length. This should face upward on the finished log so that as the cabin settles the logs will flatten and their fit will improve. To keep walls level, alternate the wide and narrow ends of the logs as shown. Use a plumb bob to check verticals and an oversized square made from 2 × 4 lumber to make sure corners form right angles.

Hoisting logs into place
Hauling logs to the top of the wall is a major undertaking. One common system uses a block and tackle hung from the top of a gin-pole tripod. Another combines a block and tackle for mechanical advantage with poles for leverage. Instead of a block and tackle, a so-called come-along ratchet hoist can also be used. It is slow but can be operated safely by one person. Acome-along can also be used to draw wall logs tightly together.
Inclined skids, a pioneer device, can be used to roll logs upward. skids should form a 30° angle and be notched at ends to hold them in place on the wall. Tie ends of rope to a wall log already in place; pass center of rope under the log being raised. Tie another rope to center of first rope, and haul on free end to roll log up ramp. Have two persons guide the log, and never stand between the skids when hauling the log upward.

Alternate courses to keep the walls level
Precise leveling of log walls is not necessary. Compensate for the natural taper of logs and prevent the accumulation of large errors by laying each course of logs so that the thick ends join the thin ends. Alternate 
Roof pitch determines purlin location. Cut vertical posts to height of roof peak and set them against center of end walls (far left). stretch wire from posts to wall sides as a guide when installing purlins and trimthe thick and thin ends vertically as well to avoid high corners when the walls are completed.

Working with short logs
Short logs can be lapped and spiked together end to end provided the joint does not occur over a wall opening or beneath a joist or beam requiring support. Many kit homes make use of this joint. The French-Canadian pioneers introduced the piéce-en-piéce construction method. slotted vertical posts are used to anchor short horizontal logs notched to fit the grooves. Piéce-en-piéce construction is excellent for building long walls, even with small diameter logs. Be sure to provide a firm foundation. Horizontals may be pegged after settling is completed.

The Finishing Touches: Shakes and Chinking

Rafters stand a few inches above the sills they rest upon, with the result that there are narrow spaces between the top of the wall and the underside of the roof. These spaces are generally filled with short segments of lumber known as snowblocks, or birdstops. Fit them as shown in the illustration at upper right, either between rafters or on each side of the plates. In warm areas the gaps are often screened without being plugged in order to provide increased ventilation.
Most cabin roofs are surfaced with wooden shakes or shingles, materials that can either be purchased in a lumberyard or made by hand (see Converting Trees Into Lumber, p.16). Standing-seam sheet-metal roofing or asphalt shingles may also be used; both are long-lasting, durable, and attractive. Shakes are slabs of wood split from straight-grained, knot-free sections of logs. They should be about inch thick and 18 to 30 inches long. Shingles are thinner and less rough-hewn than shakes. Both are traditionally made from cedar, oak, or cypress and must be completely seasoned before use; otherwise splitting will occur at the nailing points as the wood shrinks. Shakes and shingles are sold in lots called squares. Each lot contains four bundles, and each bundle will cover 25 square feet of roof. Nail shakes and shingles along the roof in overlapping rows.
Old-fashioned roofs were not insulated. The shakes or shingles were nailed directly to the purlins running the length of the roof or fastened to rows of furring strips nailed horizontally across the rafters. Skins or rugs were sometimes placed on the floor of a full loft to retain heat in the lower room; the upper storyremained cold. Modern roofs are decked over, sealed with a moisture barrier to prevent condensation, and completely insulated with urethane, styrofoam, rock wool, or fiberglass. Openings for the chimney, stovepipe, and vent stack should be flashed with aluminum or copper to prevent leaks. There are several methods of constructing insulated roofs; two of the most common are shown below. Insulation requirements vary according to climate zones (see Making Your House Energy Efficient, pp.58–64).

Two Ways to Insulate

Rigid insulation is more expensive than the soft type but requires less lumber when it is being installed. Nail pine decking boards across rafters. Cover with plastic moisture barrier. Lay insulation board over plastic. Nail 1 x 3 furring strips through insulation to rafters. Cover with shakes, shingles, or metal.Soft insulation is laid in channels between spacers and is protected by plywood sheathing. Allow airspace as shown. Lay plastic moisture barrier atop decking and toenail 2-in.-thick spacers through decking to beams. install insulation and sheathing, and cover with shakes, shingles, or other roofing.

Covering the Roof

Snowblocks, also called birdstops, seal gaps between rafters along the wall tops. Trim log sections or lumber to size; bevel to match roof pitch. insulation can be placed as shown. in warm climates screening is often installed instead of snowblocks.Start roof with double row of shakes (or shingles) at bottom. Overlap each row, leaving exposed only a third of length of shakes beneath. space shakes 1/2 in. apart and use only two nails per shake. Tar paper between rows reduces leakage.
Use galvanized nails to fasten shingles at ridge cap. Alternate the butt joints of top course shingles and blind-nail them as shown. For added moisture protection install metal flashing over roof peak beneath final row of shingles.

Chinking the Gaps

Unless you have used the chinkless construction technique shown at right, your most important finishing-up job will be to chink the gaps between logs. Traditionally, chinking was done with clay and had to be repeated frequently until the logs were completely settled. Fiberglass insulation, temporarily covered with trips of plastic and later chinked permanently with mortar, saves labor and requires little additional maintenance.
Once the cabin is weathertight, other finishing projects may be completed at leisure. These include wiring, plumbing, any interior partitions, wood stoves, fireplaces, and chimneys. Interior log walls can be covered with two coats of clear urethane varnish for a durable, washable finish. Spray the exterior of the cabin with preservative every two to three years.

Tips on wiring
Plan ahead for wiring. Chinkless construction and wiring that runs beneath floors or drops from above may require boring holes through logs during assembly. Wiring can also run behind baseboards and between logs. Bevel log ends to run wires vertically behind a doorframe molding. Check local codes and have an electrician supervise.strips of plastic and later chinked permanently with mortar, saves labor and requires little additional maintenance.
Once the cabin is weathertight, other finishing projects may be completed at leisure. These include wiring, plumbing, any interior partitions, wood stoves, fireplaces, and chimneys. Interior log walls can be covered with two coats of clear urethane varnish for a durable, washable finish. Spray the exterior of the cabin with preservative every two to three years.

Tips on wiring
Plan ahead for wiring. Chinkless construction and wiring that runs beneath floors or drops from above may require boring holes through logs during assembly. Wiring can also run behind baseboards and between logs. Bevel log ends to run wires vertically behind a doorframe molding. Check local codes and have an electrician supervise.First step in chinking is to pack insulation between logs, cover it with metal lath, and seal it temporarily with strips of clear plastic sheeting. After logs have seasoned (up to one year) apply mortar over lath. Use one part sand, three parts Portland cement, plus a handful of clay or lime for a stickier mix. Repair chinking periodically as logs settle.

Chinkless construction
Chinkless notching eliminates gaps between logs, making periodic chinking with clay or mortar unnecessary. Extra building time is needed, however, since each log must be grooved and filled as it is laid in place. First, cut round notches in ends of top log to approximate fit, allowing a gap of about 2 in. between it and lower log. Then, with dividers or log scribing tool, scribe both sides of log, transferring contours of bottom log to underside of top log. Finish cutting the round notches to the newly scribed lines, then make V-notch and channel along the length of the log, using the scribed lines as a guide. Pack channel with fiberglass insulation, and roll log into place on wall.